The handling of fluids, such as air, have been accomplished by the use of various types of valves or dampers. Air valves or dampers in heating and ventilating applications require large, substantially unimpeded passages through which air flow can be directed. Typically, air flow has been handled in ducts by the positioning of a damper which is operated by some type of motor and actuator. These structures, while adequate for handling of air flow, tend to have problems with leakage and noise.
Sleeve valves have been introduced into this type of control environment. A sleeve valve is a tube or sleeve like member made of a pliable, non-porous material attached to two collars or rings at the ends of the valve means. One collar or ring is held in a fixed rotational manner while the other end is rotated. The relative rotation of the flexible sleeve shortens the length of the sleeve slightly, and allows the pliable or flexible material to close down to restrict the passage through the sleeve. This type of an arrangement can be used as a valve in a heating or ventilating application, and eliminates the need for a damper which can cause various types of problems, including noise problems.
While a sleeve type of valve can be used, a convenient and inexpensive means for providing the relative rotation of the two ends of the sleeve has not been available. The present invention is directed to an actuator means that is adapted to control a sleeve type of valve. The actuator can be an electric motor driving a gear train, or more typically would be a pneumatic motor driving a piston. The motor must have a linear or straight line output to provide a proper driving force for the valve actuator of the present invention. The linear motion of a piston driven shaft moves a slidable carriage in a fixed base. This linear motion allows a pulley means to take up a cable on the pulley means and this causes the end of the valve to rotate with respect to the other end of the valve. The cable is attached to act around the outer surface of one end of the valve. The end of the valve that does not rotate is adapted so that it can move to shorten the length of the valve to accommodate for the reduction of length of the sleeve material itself, as the valve is twisted to provide the closing action.
The present invention more particularly is directed to a structure that is readily adapted to pneumatically operated motors, and which is capable of rotating one end of a sleeve valve to operate the valve by sliding two relatively moveable members. The two moveable members are connected to the valve end by cables which cause the rotation of the valve to provide the necessary valving function.